Earth Hour 2012 is this Saturday, March 31 from 8:30 p.m. to 9:30 p.m. local time in each city worldwide. more ›

Earth Hour 2009, a global initiative created by the World Wildlife Fund, took place worldwide on Saturday, and international landmarks showed their support by turning off non-essential lighting for one hour to make a statement about conservation and climate change. More than 200 large buildings in Chicago participated in the event, dramatically changing the view of the skyline. Chicago was one of 10 U.S. Earth Hour flagship cities. The event started in Sydney, Australia in 2007, and last year it spread worldwide. Chicago participated in 2008 as one of three flagship cities. more ›